Yomotsu-Ikusa, or the army of Yomi, were beings which were led by the Yomotsu-Shikome to pursue Izanagi when he fled the underworld after seeing Izanami's face after her death.
"Demons who serve in the army of the gods of Yomi. Izanagi chased after his dead wife to the land of Yomi, but he broke the taboo and saw Izanami's unsightly face. He started to run, which angered Izanami, causing her to send the Yomotsu Ikusa after him. Just as they nearly caught him, Izanagi threw a purifying peach seed and escaped."
—Devil Summoner: Soul Hackers 3DS Compendium
Shin Megami Tensei III: Nocturne
"Demons in Japanese mythology said to have lived in Yomi, the netherworld. They are the army that Izanami sends after Izanagi."
—Shin Megami Tensei III: Nocturne Compendium
Yomotsu Ikusa's name was shortened to Ikusa.
Persona 4
Can be obtained from Shuffle Time in Marukyu Striptease. This is the only Persona that when called out (hitting a weakness or critical hit), does not have its full name read out - instead, the protagonist only says "Ikusa!".
Devil Survivor: Cverclocked
He appears on Day 4 as an optional boss labelled Netherworld Soldier. He is in Aoyama Cemetery, amassing an army of the dead, ordering them to go into town and avenge themselves. The protagonist and his friends will try and stop them, but right before the fight a man will appear and accuse them of summoning the demons, ensuring they can't let any of the undead invaders escape, making the ensuing fight much harder. Ikusa will summon Loas, Legions and Pyro Jacks to fight; some try to fight, but most will try to get around to the exit; this will cause you to lose the fight. The boss and his demons are quite overpowered and should be attacked on a second playthrough. It's also recommended you save Midori in order to ease the burden of the fight with a fourth team.
